I. Elbow Processing Methods
Elbows are the most widely used category of pipe fittings, with the most diverse processing methods. Push BendingThe most common elbow forming method. After heating the tube blank, a special pushing machine forms the elbow along the die. Suitable for manufacturing long‑radius, short‑radius, thick‑wall and thin‑wall elbows, with a wide size range and stable quality. Press BendingThe tube blank is pressed into an elbow using a hydraulic press and special dies. Commonly used for small‑batch, thick‑wall or special‑angle elbows. Pipe BendingSteel pipes are directly bent to the required angle with a pipe bender. Suitable for small‑ and medium‑diameter thin‑wall pipes, often used in on‑site construction or non‑standard angle elbows. Hot BendingSteel pipes are heated and then bent into elbows using a bending machine. Suitable for large‑diameter, thick‑wall or special‑material pipes. CastingUsed for cast iron and cast steel elbows, suitable for low‑pressure or corrosive media.
II. Tee Processing Methods
Tee processing methods depend on material, diameter and pressure rating. Hot Press FormingThe tube blank is heated, and the branch is formed using a die. Suitable for carbon steel, alloy steel and stainless steel tees; the most commonly used method. Cold Press FormingBranches are pressed at room temperature with a hydraulic press. Suitable for thin‑wall, small‑diameter tees. Welded TeeFabricated by welding the main pipe and branch pipe. Suitable for large‑diameter, thick‑wall or special‑material applications, with low cost but multiple welds. Forged TeeFormed by forging an ingot followed by machining. Suitable for high‑pressure, high‑temperature, small‑diameter tees. Cast TeeMade of cast iron or cast steel, suitable for low‑pressure pipelines.
III. Reducer Processing Methods
Hot Press FormingThe tube blank is heated and pressed into a conical shape. Suitable for carbon steel, stainless steel and alloy steel; the most commonly used method. Cold Press FormingPressed at room temperature, suitable for thin‑wall, small‑diameter reducers. SpinningThe tube blank is spun into a conical shape using a spinning machine. Suitable for thin‑wall, large‑diameter reducers. Welded ReducerFabricated by rolling steel plates or welding two pipe sections of different diameters. Suitable for large‑diameter or non‑standard reducers. Forged ReducerUsed in high‑pressure, high‑temperature, small‑diameter applications.
IV. Cross Processing Methods
Hot Press FormingSimilar to tees, two branches are formed by dies. Suitable for medium‑ and low‑pressure pipelines. Welded CrossFabricated by welding two tees or multiple pipe sections. Suitable for large‑diameter or non‑standard crosses. Forged CrossUsed in high‑pressure, high‑temperature pipelines.
V. Pipe Cap Processing Methods
SpinningA round plate or tube blank is spun into a hemispherical or elliptical shape. Suitable for thin‑wall, large‑diameter caps. StampingSteel plates are stamped into caps using dies. Suitable for small‑ and medium‑diameter caps in mass production. Welded CapMade by rolling and welding steel plates, suitable for large‑diameter or special‑shaped caps. Forged CapUsed in high‑pressure, high‑temperature pipelines.
VI. Flange Processing Methods
ForgingThe most common method. An ingot is forged into a flange shape and then machined. Suitable for carbon steel, stainless steel and alloy steel flanges. CastingUsed for cast iron and cast steel flanges, with low cost but lower strength and corrosion resistance than forged ones. Plate CuttingSteel plates are cut into flange shapes by flame or plasma cutting, then machined. Suitable for large‑diameter, low‑pressure flanges. RollingSteel plates are rolled into rings, welded and then machined. Suitable for large‑diameter flanges.
VII. Socket‑Weld & Threaded Fitting Processing Methods
ForgingAlmost all socket‑weld and threaded fittings are forged and then machined. MachiningIncluding drilling, tapping, turning sealing surfaces, etc.
VIII. Plastic Pipe Fitting Processing Methods
Injection MoldingSuitable for mass production of PVC, PPR, PE and other plastic fittings. ExtrusionUsed to produce pipes, which are then processed into fittings through secondary operations. WeldingSuch as hot‑fusion butt welding and electrofusion joining, used for PE and PPR fittings. Solvent CementingUsed for PVC fittings.
IX. Composite Pipe Fitting Processing Methods
Steel‑plastic composite fittingsUsually use steel pipes or steel parts as the base body, lined or coated with plastic, compounded by injection molding or bonding. Aluminum‑plastic composite fittingsProcessed with special dies and press‑fit structures.
X. Summary (Most Common Pipe Fitting Processing Methods)
- Elbows: Push bending, press bending, pipe bending
- Tees: Hot pressing, welding
- Reducers: Hot pressing, spinning
- Caps: Spinning, stamping
- Flanges: Forging, casting, plate cutting
- Socket / threaded fittings: Forging + machining
- Plastic fittings: Injection molding, welding
